JPH0971390A - Counterweight attachment and detachment device of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an A frame hydraulic cylinder and a counterweight on a main frame not interfere so much with each other in a non-working position of an A frame. SOLUTION: Respective upper end parts of a pair of left and right A frame front leg 5a and A frame rear leg 5b of an A frame 5 are connected to an A frame shaft 5c free to revolve, and their respective base end parts are connected to a main frame 2 free to revolve. An upper end part of an A frame hydraulic cylinder 18 is connected to the A frame 5 free to revolve, its base end part is connected to the main frame 2 free to revolve, and a connecting position of the base end part of the A frame hydraulic cylinder 18 and the main frame 2 is arranged in front of the main frame 2 concerning the A frame front leg 5a. Consequently, the A frame hydraulic cylinder 18 is constantly positioned in front of the A frame front leg 5a at the time of attaching and detaching counterweights 9a, 9b by moving the A frame 5 between a non- working position and a working position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a counterweight attaching / detaching device for a construction machine for attaching / detaching a counterweight by undulating an A-frame by expanding and contracting an A-frame hydraulic cylinder.

[0002]

2. Description of the Related Art FIG. 5 is a side view of a mobile crane.
FIG. 6 is a view on arrow B of FIG. In the figure, 1 is a lower traveling body that can be driven by crawlers, 2 is a main frame of an upper revolving body 3 that can be swiveled, and a boom (not shown) is provided at the front part (right side of the figure) of the main frame 2. . Four
Is a hoisting winch that hoists the boom, and 5 is an A frame around which a rope (not shown) unwound from the hoisting winch 4 is wound. The boom is hoisted by adjusting the amount of rope unwound from the hoisting winch 4. Let

The A frame 5 has a pair of A frame front legs 5a rotatably connected to a mounting portion 2a of the main frame 2 by a pin 51 and a rear end of the main frame 2 by a pin 52. And a pair of A frame rear legs 5b rotatably connected to each other, and an A frame shaft 5c to which the respective tip portions of the A frame front legs 5a and the A frame rear legs 5b are rotatably coupled. The A frame rear leg 5b is composed of a plurality of links, and expands and contracts as the A frame 5 rises and falls. Reference numeral 8 is an A-frame hydraulic cylinder that raises and lowers the A-frame 5.
Is rotatably connected to the main frame 2, and the tip portion is rotatably connected to the A frame shaft 5c. 9
Reference numerals a and 9b are counterweights attached to the rear end of the main frame 2 of the upper swing body 3.

When the A-frame hydraulic cylinder 8 contracts, the A-frame 5 falls rearward of the crane, and when the A-frame hydraulic cylinder 8 extends, it rises. Counter weights 9a, 9b
When the main frame 2 is attached to or detached from the rear end of the main frame 2, the A-frame hydraulic cylinder 8 is expanded and contracted to raise and lower the A-frame 5, and the ends of a pair of hydraulic cylinders 10 rotatably connected to the A-frame shaft 5c. The section 10a is connected to the counterweight 9a,
The counterweights 9a, 9 are connected to the connecting portion 91 of 9b.
Suspend b. As a result, the counter weights 9a, 9
b moves in the front-back direction of the crane due to the ups and downs of the A frame 5, and moves in the up-down direction due to the expansion and contraction of the hydraulic cylinder 10.

[0005]

By the way, since the mobile crane is transported in a state in which the A frame 5 is tilted rearward as shown by the chain double-dashed line in FIG. 5, the counterweight 9 is used.
The a and 9b are shaped so as not to interfere with the A frame 5 and the A frame hydraulic cylinder 8, for example, as shown in FIGS. 5 and 6, concave portions are formed in the upper portions of the counterweights 9a and 9b to form a U-shape. There was a need. Since the width dimensions of the counterweights 9a and 9b are limited by the width dimension of the upper swing body 3, the thickness dimension in the front-rear direction is increased by an amount corresponding to the volume of the recess formed in the upper portions of the counterweights 9a and 9b. , The rear radius of the crane will increase.

An object of the present invention is to provide a counterweight attaching / detaching device capable of reducing the rear end radius of the construction machine in a construction machine for attaching / detaching the counterweight using the A frame.

[0007]

When the invention of claim 1 is described in association with FIG. 1 showing an embodiment of the invention, a pair of left and right whose base end portions are rotatably connected to a main frame 2 respectively. Of the front leg 5a and the rear leg 5b, and an A frame 5 having an A frame shaft 5c that rotatably connects the upper end portions of the left and right front legs 5a and the rear leg 5b, respectively, and the base end portion is rotated to the main frame 2. An A-frame hydraulic cylinder 18 which is movably connected and whose upper end is rotatably connected to the A-frame 5 to move the A-frame 5 between a non-working posture and a working posture. The present invention is applied to a counterweight attaching / detaching device of a construction machine that moves between the non-working posture and the working posture to attach / detach the counterweights 9a and 9b, and connects the base end portion of the A-frame hydraulic cylinder 18 and the main frame 2. The formation position and located in front of the main frame 2 with respect to the front leg 5a to achieve the above object. Like the counterweight attaching / detaching device according to the invention of claim 2,
The counterweight suspending hydraulic cylinder 10 provided on the A frame 5 is further included, and the counterweight suspending hydraulic cylinder 10 is expanded and contracted when the A frame 5 is in a non-working posture and a working posture to counterweights 9a and 9a.
The counter weights 9a, 9
b may be attached and detached.

Since the A-frame hydraulic cylinder 18 is located ahead of the front legs 5a, the A-frame hydraulic cylinder 18 and the counterweight 9 mounted on the main frame 2 when the A-frame hydraulic cylinder 18 is extended and the A-frame 5 is tilted.
The amount of interference with a and 9b can be reduced.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to make the present invention easy to understand. However, the present invention is not limited to the embodiment.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The same parts as those in FIGS. 5 and 6 are designated by the same reference numerals. FIG. 1 shows an example in which the counterweight attaching / detaching device according to the present invention is applied to a mobile crane, and is a side view of the mobile crane. The A frame 5 includes a pair of front legs 5a, a pair of rear legs 5b, and a pair of A frame hydraulic cylinders 18. The base end of the A frame front leg 5a is connected to the main frame 2 by a pin 51.
Is rotatably connected to the mounting portion 2b of the A frame rear leg 5
The base end of b is rotatably connected to the main frame 2 by a pin 52, and the front ends of the A frame front leg 5a and the A frame rear leg 5b are rotatably connected to the A frame shaft 5c. .

The tip of the A-frame hydraulic cylinder 18 is A
A connecting portion 53 provided on the frame front leg 5a is rotatably connected by a pin 82, while a base end portion of the A-frame hydraulic cylinder 18 is rotatably connected by a pin 81 to a mounting portion 2b of the main frame 2. ing. Mounting part 2b
Is the base end of the A-frame hydraulic cylinder 18 and the mounting portion 2b.
It is formed so that the connection position with the front frame 5 of the A frame is located in front of the main frame 2, that is, on the boom mounting side. Here, the connection position being in front of the main frame 2 with respect to the A-frame front legs 5a means A
The pin connection point at the base end of the frame hydraulic cylinder 18 is in the front direction of the main frame 2 with respect to the axis of the A frame front leg 5a, that is, in the figure, the pin connection point is the A frame front leg 5a.
It is required to be on the right side of the axis of a. Therefore, the pin connection point at the base end of the A-frame hydraulic cylinder 18 does not necessarily have to be in front of the pin connection point at the base end of the A-frame front leg 5a with respect to the horizontal direction. The above requirement is satisfied if it is on the right side of the figure with respect to the axis of the frame front leg 5a. In FIG. 2, which is a view from the arrow B of FIG. 1, the A frame front leg 5a and the A frame hydraulic cylinder 18 are hidden by the A frame rear leg 5b and are not visible.

FIG. 3 is a diagram for explaining the attaching / detaching operation of the counterweight. When the counterweight 9a is attached to the main frame 2, first, the A-frame hydraulic cylinder 18 is extended and the A-frame 5 is tilted backward, and then the hydraulic cylinder 10 is extended and placed on the tip portion 10a and the ground. The connecting portion 91 of the counterweight 9a is connected. Next, the hydraulic cylinder 10 is contracted to reduce the counterweight 9a.
, The A-frame hydraulic cylinder 18 is contracted to raise the A-frame 5, and the counterweight 9a is moved above the mounting position of the main frame 2. And
After extending the hydraulic cylinder 10 to lower the counterweight 9a to the mounting position, the tip end portion 10a of the hydraulic cylinder 10 and the connecting portion 91 are disconnected, and the counterweight 9a is fixed with a bolt (not shown). The same applies to the counterweight 9b, and when removing the counterweights 9a and 9b from the main frame 2, the reverse procedure is performed.

In this embodiment, even when the A frame 5 is tilted from the working position shown by the solid line in FIG. 1 to the non-working position shown by the two-dot chain line in FIG. Since the connecting portion between the main frame 2 and the mounting portion 2b of the main frame 2 is located forward with respect to the A frame front leg 5a, the A frame hydraulic cylinder 18 does not interfere with the counterweights 9a and 9b mounted on the main frame 2. Therefore, the counterweights 9a and 9b need only be formed with recesses in the portions where the A frame interferes, as shown in FIG. 2, and the recesses can be smaller than in the conventional case. As a result, the counterweight 9a corresponding to the volume of the recess,
The increase in the thickness dimension of 9b becomes small, and the increase in the rear end radius of the crane can be suppressed. The counterweight attaching / detaching device according to the present invention can be applied not only to the above-mentioned crawler crane but also to a mobile crane such as a truck crane.

FIG. 4 is a modification of the above-described embodiment, in which the base end of the A-frame hydraulic cylinder 18 is attached to the connecting portion 11 attached to the attaching portions 2a and 2c of the main frame 2 by the pins 51 and 83. It is rotatably connected by a pin 81. The pin 51 fixes the connecting portion 11 to the mounting portion 2a and rotatably connects the base end portion of the A frame front leg 5a to the mounting portion 2a. The other structure is similar to that of the above-described embodiment, and the A-frame hydraulic cylinder 18 is provided.
Connecting part 1 attached to the base end of the main frame 2
Since the connecting portion with 1 is located forward with respect to the A frame front leg 5a, the A frame hydraulic cylinder 18 does not interfere with the counterweights 9a and 9b mounted on the main frame 2.

Instead of the hydraulic cylinder 10 described above, the present invention can be applied to other weight lifting and lowering devices, for example, those using a chain block. Further, if the weight can be hoisted and hung by moving the A frame between the working posture and the non-working posture without providing a weight hoisting and lowering device,
In particular, it is not necessary to provide a weight lifting and lowering device.

[0016]

As described above, according to the present invention,
Since the connection position between the base end of the A-frame hydraulic cylinder and the main frame is arranged in front of the main frame with respect to the pair of front legs, the A-frame hydraulic cylinder is expanded and contracted to move the A-frame to a non-working posture. Even if the counterweight is moved between the work position and the work posture, the amount of interference between the A-frame hydraulic cylinder and the counterweight mounted on the main frame can be reduced, so that the increase in the thickness of the counterweight can be small. The increase in the rear end radius of the crane can be reduced. In the counterweight attaching / detaching device according to the second aspect of the present invention, since the counterweight hydraulic cylinder for lifting and lowering the counterweight is provided, the lifting and lowering work of the counterweight can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a first embodiment of a counterweight attaching / detaching device according to the present invention.
FIG.

FIG. 2 is a view taken in the direction of arrow B in FIG. 1;

FIG. 3 is a diagram for explaining the operation of the counter weight shown in FIG.

FIG. 4 is a view showing a modified example of the counterweight attaching / detaching device shown in FIG. 1.

FIG. 5 is a view showing a conventional counterweight attaching / detaching device.

FIG. 6 is a view as seen from the arrow B in FIG. 5;

[Explanation of symbols]

 1 Lower Traveling Body 2 Main Frame 2a, 2b, 2c Mounting Part 3 Upper Revolving Body 4 Elevating Winch 5 A Frame 5a A Frame Front Leg 5b A Frame Rear Leg 5c A Frame Shaft 8, 18 A Frame Hydraulic Cylinder 9a, 9b Counterweight 10 Counterweight Suspended hydraulic cylinder 51, 52, 81, 82 Pin 11, 91 Connection part

Claims (2)

[Claims] 1. A pair of left and right front and rear legs whose base ends are rotatably connected to a main frame, and an upper end of each of the pair of left and right front and rear legs which is rotatably connected. An A frame having a frame shaft, a base end portion rotatably connected to the main frame, and an upper end portion rotatably connected to the A frame.
Move the frame between non-working position and working position A
A counterweight attaching / detaching device for a construction machine, comprising: a frame hydraulic cylinder; and moving the A frame between the non-working posture and the working posture to perform a counterweight attaching / detaching work. A counterweight attaching / detaching device for a construction machine, wherein a connecting position between the mainframe and the mainframe is arranged in front of the mainframe with respect to the front leg. 2. The counterweight attaching / detaching device according to claim 1, further comprising a counterweight suspending hydraulic cylinder provided on the A frame, when the A frame is in the non-working posture and the working posture. A counterweight attaching / detaching apparatus for a construction machine, wherein the counterweight hydraulic cylinder is expanded / contracted to lift and lower the counterweight to attach / detach the counterweight.